Guiding and releasing device for sliding hoods of airplanes



Oct. 24, 1944-. J c LOBELLE 2,361,113

GUIDING AND RELEASING DEVICE FOR SLIDING HOODS OF AIRPLANES Filed April 17. 1943 3 Sheets-Sheet l Inventor Altorne 3 5 0d. 24, 1944. LOBELLE 2,361,113

GUIDING AND RELEASING DEVICE FOR SLIDING HOODS OF AIRPLANES Filed April 17, 1943 3 Sheets-Sheet 2 Inventor MIOj. o BELLL.

zllorneys Oct. 24, 1944. M. J. o. LOBELLE GUIDING AND RELEASING DEVICE FOR SLIDING HOODS OF AIRPLANES Filed April 17, 1943 3 Sheets-Sheet 3 H WA Attorney Patented Oct. 24, 1944 GUIDING- AND RELEASING DEVICE FOR.- smnmc noons F AIRPLANES Marcel Jules Odilon Lobelle, Slough, England, assignor to Messrs. R. Malcolm Limited, Slough, England, a British company Application April 17, 1943, Serial No. 483,427 In Great Britain June 11, 1942 6 Claims.

This invention relates to devices for holding and guiding sliding. hoods such as are used on airplanes and enabling them to be released instantaneously whenever required no matter in what position such hoods may be at the moment of release. Slidable hoods of the character in question are usually disposed over the pilots cockpit and they consist essentially of a canopy of translucent material, sometimes of double thickness with an air space between the two layers, and frames designed to fit over the fixed :parts of the canopy and the fuselage, and guide rails extending along the lower edges at each side adapted to work in guide tracks on the fuselage. It may be desirable to maintain air under pressure in the pilot's cockpit, and under these circumstances the sliding hood is provided with means for effecting an airtight closure along the sides and ends, generally in the form of inflatable tubular members which will make an airtight joint when extended by inflation. The hood is capable of sliding back to any extent required over the fixed part of the canopy and the fuselage, and of course when pushed back there is no air pressure'maintained, such pressure being in existence only when the hood is in the forward closed position. In front of the hood is the usual sight screen with its bullet-proof glass and so forth, while behind the sliding hood the fixed canopy over the fuselage may have transparent panels, doors and so forth, but it does not slide longitudinally.

It is essential to provide means whereby the hood can be jettisoned at any moment in an emergency. For this purpose arrangements have been made whereby the pilot can effect the jettisoning by operating handles, lever or the like simultaneously at each side of the cockpit, one by each hand, but this is not satisfactory because if one side releases before the other the hood does not part cleanly from the fuselage and may cause difiiculties. Moreover, the pilot may not have two hands available for eifecting simultaneous operation.

It is the object of the present invention to provide a guiding and releasing device for sliding hoods which will enable the jettisoning to be effected under all conditions with certainty by a single control, no matter whether the hood is under pressure internally or not, or in what position it may be at the time. For this purpose the guide tracks for the slide bar at each side of the hood may consist of an inner fixed rail and an outer hinged rail, the outer hinged rail being controlled by a mechanism which is always under outer hinged rail at each side which alone is holding it to the fuselage, will ensure that the hood can fly ofl freely under all conditions. The releasing mechanism starts the movement of the hinged rails with a powerful leverage so as to make sure that the release is instantaneous even if the hood is partly held by icing, by congealed oil, or any other obstruction to free movement.

0ne example of a suitable construction according to the invention is illustrated in the accompanying drawings, wherein:

Figure 1 shows a side view of a portion of an airplane fitted with the sliding hood, and

Figure 2 is a plan view of what is shown in Figure 1;

Figure 3 shows to a larger scale the operating mechanism by which the hood is released, parts being shown in section;

Figure 4 shows a plan view illustrated in Figure 3;

Figure 5 shows a section on the line 55 in Figure 3; and

Figure 6 is a detail view illustrating a hinged rail opened out and the hood released. v

The general arrangement of the sliding hood is best seen in Figures 1 and 2 wherein the trans- .parent portion of the hood is shown as being made of two layers of a translucent material III with an air space between them. The front of the hood is shaped as at 8' to fit over the sight screen, and the rear of the hood is shaped as at 9 to moveover the fixed hood or canopy I, which may also be of a translucent material. The sliding hood I0 is shown in dotted lines in Figure 1 in its position when fully pushed back. The lower edge of the hood l0 at each side is held in a foot piece i2 which is of metal and has a projecting portion l3 adapted to be held by the head of a guide rail 14 mounted on a longitudinal hinge at l5. Each foot piece I2 is held in place from within by a plate l6 carrying an inflatable rubber tube or tyre ll, which is shown inflated in Figure 3 but deflated in Figure 6. This tube or tyre l1 extends along the side of each foot piece 12 and also around the edge of the sight screen at the front and the frame of the fixed canopy I at the rear so that when inflated it of the mechanism will make an airtight joint around the whole circumference of the hood Ill. The operating mechanism for releasing the hinged rails I4 is supported within and upon a casing ll extending across the fuselage at the rear of the pilots cabin. The casing II has a substantial bracket 52 at each end, terminating in a disc-shaped plate 53 whereby it is secured, as by bolts 54 to the side of the fuselage. These brackets rest on the longerons 55 at either side of the fuselage, as seen in Figure 3.

Each hinged rail l4 has a lug carrying a stud l8 connected by a link l9 to a stud 20 on the end of the plunger 2| which slides in a guideway including a packing ring or gland 22 held in place by a gland nut 23 so as to prevent leakage of air around the plunger. The other end of the plunger is connected by a link 24 to a swivel member 25 pivoted at 26 in the supporting casing ll. Each swivel member 25 also has pivoted to it a forked member 28 with a stem 29 engaging in a socket in the end of a connecting rod 30 or 30". There are two connecting rods 30 and 30, each with a hook-shaped inner end so that the inner ends can overlap one another, as seen in Figure 3, in order to engage with crank pins 3| and 3| on the end of a shaft 32. This shaft is supported in a bearing or sleeve 33 carried by the casing l I, the shaft being bored out and fitted with a cross pin 34 riveted through it for engagement at the end by a suitable tool (not shown) which can be inserted in the open end to set the mechanism ready for operation. To the forward end of the shaft 32 is attached a setting lever 35. The attachment is shown as being effected by a number of screws 35 whose heads are drilled through to permit a wire 31 to be threaded through them and its ends twisted together to serve as a seal for this attachment. The boss of the setting lever is open to permit the entry of the tool before mentioned into the hollow shaft 32 for setting purposes, and the heads of the screws 36 are just clear of the internal bore through which this tool must enter.

The fixed sleeve 33 is surrounded by the coils of a substantial spring 39, one end of which is anchored to a bolt 40 projecting from the casing ll while its other end is hooked over the arm of the setting lever 35 as shown at 4|, Figures 3 and 4. The spring thus tends to turn the lever 35 clockwise in Figure 3 so as to move the connecting rod 30 toward the left and the connecting rod 3B toward the right, to rock the swivel members 25 outwardly, so thrusting theplungers 2| outwardly and opening out the guide rails l4 toward the position shown in Figure 6.

The setting lever is held in the position shown in Figures 3 and 4 by a trigger lever 42 pivoted on a stud 43 on the front of the casing II, and having a headed pin 44 projecting from it with which the notched end of the setting lever 35 engages, as clearly seen in Figures 3 and 4. A coiled spring 45 surrounds the stud 43 and has one end 46 anchored by being passed through a hole in the casing ll, while its other end 41 is hooked round the arm of the lever 42. The spring thus holds the lever strongly in the position of Figure 3 in which it is fully engaged with the notched end of the setting lever 35. To the lower end of the trigger lever 42 may be attached a cable 48 or any other means of connection for effecting the release by a single pull.

In Figures 1 and 2 the cable 48 is indicated as being a cable of the Bowden type, i. e. enclosed in a sheath, and carried around the cockpit to a button 49 at the front which the pilot can pull at any time to effect release. A branch connection from the cable 48 may also be taken to an external button 50, indicated in dotted lines in Figures 1 and 2, whereby the hood may be released from outside the cabin in case, for example, a pilot has effected a landing but has fainted or is otherwise incapable of releasing the hood himself.

In setting, the mechanism to close the hinged rails l4 around the foot pieces l2 of the sliding hood, a suitable tool is inserted in the end of the shaft 32 to engage with the cross pin 34 and to turn the shaft in a counter-clockwise direction, as seen in Figure 3. In this movement the curved surface 56 on the end of the setting lever 35 bears against the headed pin 44, pressing the trigger lever 42 toward the right until the connecting rods 30 and 30 have moved just past the position shown in Figure 3, and the lever 35 has risen just far enough for the headed pin 44 to slip under the nose of the lever 35. Then, when the shaft is released, the parts take up the position shown in Figure 3. The hood can now be pushed backward and forward along its guide rails provided the tyre I! is not inflated, and when it is desired to make the cabin airtight this can be effected by inflating the tyre I! as already described. The hood of course cannot be moved backwards and forwards so long as the tyre is inflated. The hood can be released however at any time whether an air pressure is being maintained within it or not, and no matter what position the hood may occupy, merely by a direct pull on the cable 43, withdrawing the headed pin 44 from under the setting lever 35, and allowing this to be turned freely under the action of the spring 39. Under this action the setting lever 35 and the shaft 32 are free to make about half a turn, while the crank pins 3| and 3! substantially change places and the connecting rods 30 and 30 are pushed outwards as already described. A convenient form of stop to cushion the end of this movement is a block 51 of rubber or like material, secured in a fitting 58 on the wall of the casing I l, against which block the connecting rod 30 strikes as its crank pin 3| rises at the left hand side in Figure 3, but any other form of stop device which is suitable can of course be used.

The mechanism described is sufiiciently powerful in operation to open out the guide rails I4 with certainty, no matter whether they are gummed up with oil or partially obstructed by frosting and so forth. At the beginning of the turning movement of the setting lever 35 the leverage is very high, and the connecting rods 30 and 30 only begin to move longitudinally to an appreciable extent after several degrees of turning movement of the shaft 32, by which time considerable inertia has come into play in the retation of the shaft 32 and the setting lever 35 which will assist in breaking down any resistance to movement.

The frame of the hcodlll, including the foot pieces I2 on the one hand, and the hinged guide rails 14 on the other hand, are preferably made of light metal such as an aluminium alloy, and in the examples shown the length of the guide rail H! at each side of the fuselage is such that it only requires holding up by the one releasing mechanism at each end of the casing H to ensure the effective support and guidance of the hood. If necessary in case the hood has to be substantially longer for example, it is possible to duplicate the part of the releasing mechanism which supports the hood by providing additional linkage I8, [9, 20, plungers 2i and so forth at another point along the length of the rail, and to connect them up to additional swivel members such as 25 mounted to turn on a spindle with the directly operated swivel members 25 by replacing the stud 26 at each side of the fuselage by a spindle 59, shown in dotted lines in Figure 2, extending along to the additional releasing mechanism. In this way the one operating and release mechanism can control each hinged rail [4 at two or more points, while a single control will effect the release with certainty and simultaneously of both hinged rails so that the hood is completely released by a single manipulation.

Many other details in the mechanism may be modified and parts replaced by their obvious alternatives without departing from the scope of the invention, but in all cases the rails must be held in their operative position by a catch device which can readily be released and will then allow a source of energy such as a coiled spring to come into play to effect the immediate and forceful opening out of both guide rails.

Iclaim:

1. The combination with an aircraft hood of guiding and releasing means therefor comprising rail tracks at each side, hinges for each of said rail tracks, and slide surfaces on said hood adapted to be engaged by said rail tracks when held up about their hinges, spring means which when tensioned tend to open out said rail tracks simultaneously abouttheir hinges, a trigger mechanism adapted to restrain release of said spring means, and manual control means adapted to operate said trigger mechanism for releasing both of said rail tracks simultaneously.

2. The combination with an aircraft hood of guiding and releasing means therefor comprising two rail tracks one at each side of said hood, hinge supports for said rail tracks, slide surfaces on said hood adapted to be engaged by said rail tracks when held up about their hinges, linkage between each of said rail tracks and a single control member therefor, spring means tending to turn said control member in a direction such as to spread said linkage and open out said rail tracks about their hinges, and trigger mechanism preventing release of said spring means until said trigger mechanism is operated to effect such release.

3. The combination with an aircraft hood of guiding and releasing means therefor comprising two rail tracks one at each side of said hood, hinge supports for said rail tracks, slide surfaces on said hood adapted to be engaged by said rail tracks when held up about their hinges, a shaft, crank pins thereon, and linkage connecting said crank pins operatively to said rail tracks, a spring which when tensioned tends to turn said shaft in a direction such as to move said linkage in a direction for releasing said hinged rail tracks, trigger mechanism and manual control therefor adapted to hold said shaft and spring ing said crank pins operatively to said rail tracks,

a spring which when tensioned tends to turn said shaft in a direction such as to move said linkage in a direction for releasing said hinged rail tracks, trigger mechanism and manual control therefor adapted to hold said shaft and spring in position in which said spring is tensioned, and to release the same at will, stationary guide surfaces adjacent to said hinged guide surfaces, inflatable sealing means for said hood upon said stationary guide surfaces, and inflatable sealing means adapted to co-operate with the other terminal parts of said hood which are not within said guide surfaces.

5. The combination with an aircraft hood of 5 guiding and releasing means therefor, comprising two rail tracks one at, each side of said hood, hinge supports .for said rail tracks, slide surfaces on said hood adapted to be engaged by said rail tracks when held up about their hinges,

a shaft, crank pins thereon, and linkage connecting said crank pins operatively to said rail tracks, said linkage including plungers and stufiing boxes therefor adapted to restrain leakage of air around said plungers, a spring which :15 when tensioned tends to turn said shaft in a direction such as to move said linkage in a direction for releasing said hinged rail tracks, trigger mechanism and manual control therefor adapted to hold said shaft and spring in position in which said spring is tensioned, and to release the same at will, stationary guide surfaces adjacent to said hinged guide surfaces, inflatable sealing means for said hood upon said stationary guide surfaces, and inflatable sealing means adapted to co-operate with the other terminal parts of said hood which are not within said guide surfaces.

6. The combination with an aircraft hood of guiding and releasing means therefor comprising two rail tracks one at each side of said hood, hinge supports for said rail tracks, slide surfaces on said hood adapted to be engaged by said rail tracks when held up about their hinges, linkage between each of said rail tracks and a sin gle control member therefor, said linkage including plungers and stufling boxes adapted to restrain leakage of air around said plungers, means for sealing the edges of said hood in a substantially airtight manner, spring means tending to turn said control member in a direction such as ,to spread said linkage and open out said rail tracks about their hinges, and trigger mechanism preventing release of said spring means -until said trigger mechanism is operated to effect such release.

MARCEL JULES ODILON LOBELLE. 

